This invention relates to a fixing structure for a flexible bellows for a marine propulsion device and more particularly concerns the end connection and sealing structure of the flexible bellows within the outboard drive unit.
Marine inboard/outboard drive units generally include an inboard engine having an output shaft and an outboard drive unit having an input shaft coupled by a universal joint to the engine output shaft. The universal joint is enclosed within a gimbal ring and a casing of the outboard drive unit. A flexible bellows covers the universal joint and is secured to the outboard drive unit to form a water tight seal. A known technique for securing the bellows to the outboard drive unit is to affix the bellows end to the outer periphery of a projection defining a cylindrical opening within the outboard drive casing. A fastening band or ring exerts a radially inward force against the outer periphery of the bellow end against the outer surface of the cylindrical projection of the retaining casing. This technique is difficult to install and inspect during assembly of the outboard unit because the fastening band is housed within the casing.
In another known technique, the rear end of the bellows is inserted into an opening in the casing and secured by the attachment of the main housing of the drive unit. This technique causes problems since the seal cannot be visually checked once the outboard drive unit is assembled.
It is therefore the principal object of the present invention to provide a sealing means for a flexible bellows end that can be visually inspected during assembly.
It is another object of the present invention to provide a retaining sleeve which is capable of securely sealing a flexible bellows end portion in an outboard drive casing.
It is another object of the present invention to provide a retaining sleeve which may be easily installed and removed during the assembly of the outboard drive unit.